Sunday, 15 October 2017

All the UKs frequencies on Google Earth?

Yesterday, someone pointed out to me that it was possible to download the whole of Ofcoms license allocation database, as a comma separated variable delimited file. This is the list of who holds what licenses for what specific frequencies, not amateur licenses, or users of license free channels.

This info of course is of great interest to scanner users, but the original .csv file rocks up at over 70MB and around a third of a million entries!

Now, wouldnt such a file, showing who is using what frequencies and where, be great on Google Earth?

Glutton for punishment that I am, and recognized at work as the Google Earth Gnome, I foolishly set about trying to convert a 70MB .csv file into a workable set of .kmz files!

Key to this, are three steps - First, remove all non-geographical entries. These are frequencies and users allocated on a nationwide basis, and hence have no position information for Google Earth to work with. Second, remove all duplicates. In this case, a duplicate entry is one where the same user, is listed with the same frequency, in the same location. A frequency can be used by the same user in a different location, thats a valid entry, as is a different user using the same frequency, etc. And third, split the file into manageable chunks.

The first two operations have been done using the data handling tools in Microsoft Excel. The third needed some thinking about. I opted to split the file into separate files based on area, and chose to use the Ordnance Survey 100km gridsquares

Most areas, this creates an easily handled file size. The exception is grid TQ, which covers that there London. The density of allocations in London is such that I have had to split that file into four, and perhaps even more, based on frequency band.

The resulting .csv files, can be imported direct into Google Earth. Ultimately, I wish to convert them to .kmz files that are native to Google Earth and can be distributed, such that any user can just open the file and it will work. Imported .csv files require some setting up.

The above pic is a screenshot of my Google Earth Pro with three of the gridsquare files imported and enabled.

Tuesday, 10 October 2017

Can my blog save you money?

Quite possibly!

Just recently, I received an email from British Gas, my energy supplier at the time. This email informed me that my gas and electricity bills were not only going to go up by a extortionate amount, but also that they were ending the dual fuel discount as well. The general gist of the email was "pay up or sod off"...

... so I sodded off!

After a lot of research, trawling comparison sites and the like, I narrowed down a number of new suppliers, which were smaller, much cheaper, and it seemed more ethical than British Gas. And out of these, one caught my eye - Bulb.

Bit of a gimmicky name for an electricity supplier! But, the more I read, the more I liked what I was reading. Committed to customer service, committed to renewable energy sources, and online open forum for customers and non-customers alike. So, after looking at my potential savings, I signed up with them.

The link below ive provided for anyone who is considering switching suppliers, to take a look and do your own research into them. Take a look at their reviews online as well.

This was just over a month ago, and ive just submitted my second set of meter readings. All seems to be going very well so far, and any queries ive had have been dealt with by their team via the forums swiftly. So far im happy with them and alls going well. Im on a list for the trial of next generation smart meters as well. The only odd part is that payments are done initially by debit card, but you can call and set up a direct debit (I must remember to do this!), and also, they work on an advance payment system, which means you actually pay up front, and if you overpay either it holds on your account or you can ask for it rebated. This seems very odd at first, but in many ways it does make sense.

So, your thinking, all well and good, but how does that help your readers save money?

Well, its simple - If you sign up to change your supplier to them, using a link that I will provide below, they give you a £50 initial credit! And, whats even better - they give me one as well!

Heres the link -

I would suggest this - If your considering changing your energy supplier - go and research Bulb online, also research other suppliers, and find the one that is right for you. IF, you find that Bulb suits you, then use my link above to get yourself, and me, fifty quid!

Im not going to try to convince you, coerce you, or force you! But, it makes sense to me to take up an offer if your switching anyway, so my referral link is there above for you, should you choose to use it.

Clear as mud

Well, for some reason, the plum wine isnt clearing. Wine making has taken up pretty much most of my spare time recently, and shortly some beer brewing will also join my activities, now I have a nice big fermentation bucket!

Thats not to say there is no radio planned! Due to workload, and my walking mate Bob M1BBVs change of career, walking and field radio have been rather sparse. However, hopefully soon (next few weeks) we will be back out there. A few rail trail walks and some long outstanding SOTA is on the horizon!

Anyway, back to the wine! It would seem the problem here is a protein or pectin haze. As this wine has already has two-part finings (isinglas/gelatine and keiselsol) ive decided to try another electropositive fining agent,  this time Bentonite, which is known for its ability to drag proteins out of suspension. Its a bit more faffy to use than other finings, as the extremely hygroscopic particles of this volcanic clay must be hydrated into a slurry prior to use.

But, it does also give me a chance to exchange the airlock and bung fitted, with a solid bung, freeing up the airlock for other use. Hopefully now this wine will clear over the next couple of days, and can then be bottled - which will free up the demijohn for racking off one of the other wines!

Monday, 2 October 2017

Variant "WOW" wine

Ive not been on here much lately, mostly due to work and the like, but that doesnt mean ive not been busy,

I have, just not with radio!

Instead, Ive been wine making. This is something I always intended to to do, but never got around to, despite my experiences of it as a kid helping the chap over the road.

But it occurs to me that my blogs are a good place to record experiments in this line. To date ive completed and drunk a 5L kit Cabernet Sauvignon, I have an apple wine, using my own fruit, bottled. A plum, again using my home grown fruit, in the process of clearing. I have a kit chardonnay bubbling away in early secondary, and a strawberry getting close to the end of fermentation.

This morning, I decided to quickly throw on a "WOW" variant. Now, WOW stands for Wurzels Orange Wine, and in its pure form of course uses oranges. A 'variant' generally refers to a wine made using store bought juices. This is what I have gone for.

This will be an Apple, Watermelon and Raspberry wine. No messing about with hydrometers for this one! Just 3L of 100% juice and 1100g total sugars.

Heres the recipe -

1L 100% red grape juice
2L 100% apple, watermelon and raspberry juice*
820g granulated sugar
1L water
1 cup strong tea (tannin)
1/2 tsp Pectolase
1 tsp glycerine
2 tbsp lemon juice (acid)

*1L in must, 1L in fridge for topping up

A general purpose wine yeast, activated in a  cup of warm water with 2 tsp sugar, was the first thing to get started. After that, the demijohn, airlock and other needed kit was sterilized. Luckily these days, with everyone so health conscious, cartons of juice have the sugar content printed on them. So, I knew I had 308g of sugars in the juice, so needed to add around 808g. With the variability of scales, I probably put 820g in. I didnt mix the sugar well enough with the 1L extra water, so have just had to spend 5mins swirling the must to dissolve the excess. With all the additives, sugar, water and first two juices in, theres a bit over 3L of must, coming to just below the shoulder of the demijohn. The lemon juice provides the acidity, whilst the strong cup of tea provides the tannins. A bit of glycerine to improve mouth feel, and some pectolase enzyme to help break down any fruit pectins.

I pitched the yeast once everything else was in, and when checked this afternoon (about 6 hours later) it was bubbling at about four every minute. So, after getting all the extra sugar dissolved, ive now transferred the demijohn to my usual 'production line', where it can now stand and crack on with primary fermentation. As WOW wines can often become somewhat 'lively', this one is stood in a drip tray!

Once its done with primary, maybe three days or so once it gets properly started, i'll top it up with the remaining juice. This wine should complete secondary in under two weeks, and once cleared should be drinkable more or less straight away.

Saturday, 29 July 2017

New Mode Time - MSK144, and Random MS

With propagation down, and the weather rather hit and miss, I thought i'd try my hand at something new.

To make things difficult for myself, I picked a little known datamode protocol - MSK144, and an underused band for which I have only a low, fixed azimuth beam - 6m.

And to ensure I really did have the hardest time possible, this mode is used for a difficult propagation path - Metero Scatter!

The principle behind meteor scatter is fairly straightforward. Everyday, thousands of minute particles of space dust, usually no larger than a grain of sand, collide with the earths atmosphere, and are burnt up by the protective layers above us. Those grains, while out in space, are Meteoroids. As they pass through the atmosphere and burn up, they become Meteors. Should any part of it survive its encounter and reach the earths surface (which would need to have been a rather big bit of rock!) the remains are Meteorites. On any clear night from a suitably dark location, you can see a few random meteors. Those of you of a Disney fairytale princess persuasion may wish upon these shooting, or 'falling' stars - those with a hundred watts or more of throbbing RF and suitable software can make contact over them!

As the meteor burns up, it leaves behind it a trail of ionized particles. It is against this trail, a fleeting moment lasting from a few tenths of a second to a handful of seconds for a big, pebble sized meteor (which visually would produce a fireball or 'bollide') that we fling our radio messages, hoping to scatter enough signal from the trail to reach our partner station.

At certain times of the year though, the earth passes through streams of dust left behind by the passage of comets through the solar system. At these times, there is a marked increase in the number of meteors, and these are known as Meteor Showers. As with any event that affects propagation, these bring the latent operators out of the woodwork. However, the next shower, the Perseids, is several weeks away.

At times like this, you either set up a 'sked' with a particular station, or call CQ to try and make a random QSO...

As you can imagine, A random MS QSO is hard work! Your facing a combination of limited beamwidth (the same trouble that we have photographing meteors - your limited lens field of view means the meteor you see with your eyes is usually not in the cameras view!), rare and fleeting propagation, and few, if sometimes indeed any, other stations using the same mode and same frequency.

But, there are ways around! And thanks to the internet and fast CPUs, its a bit easier! We can announce on dedicated chat forums that we are calling, there are strict rules and message formats, and there are modulation protocols that run fast messages to increase the chance of a usable reflection. In the old days, MS was done by high speed morse! Now, its done using fast data modes such as MSK144, JT6M and FSK441.

But, despite all that, a random MS QSO is still a challenge! To state how much of a challenge, well, Ive probably spent 50h on it in the past few days, transmitting for maybe 2h total key-down time, and ive made two contacts!

The screenshot above shows a meteor 'ping'. The two halves of the window are 15 seconds long, and my transmit slot was 15 seconds between them. In 30 seconds then, only a single brief meteor passed at the right altitude, and position, between my station and that of Jurgen DK4AN. But, it was enough!

Sometime in the previous five minutes or so, a meteor had also passed that point, during one of my 15s Tx slots. Its decaying trail lasted long enough to reflect enough of my MSK144 message to Jurgen. The meteor in the image above, reflected his reply!

The software Im using is Joe Taylor W1JT's WSJT-X v.1.7. Joe is the chap who brought us WSPR plus a host of other modes for weak signal or fleeting propagation use - JT65, WSPR, JT9, JT6M etc etc. A new mode from him FT8, is rapidly gaining popularity! My antenna in this case is a 3 el yagi for 6m at the low height of about 15ft, fixed in direction to 120 degrees (roughly SE), the radio my Alinco DX-70TH running 100W. I am also using the VHF/UHF chat room of ON4KST online, in order to help co-ordinate my effort with others!

Around five minutes later, the above meteor 'burst' occurred. This was probably a slightly bigger grain of dust, maybe about the size of a bit of gravel, and it seems to have burnt up in pulses, a bit like when you see a naked eye meteor that seems to blaze up a couple of times. During this burst, I copied DK4AN again, decoding his message a couple of times. Now, as you can see, the messages are very short and direct. No data is wasted. The format is strictly controlled to ensure the right messages are sent and theres no confusion. As it happens, the WSJT-X program allows you to select 'Auto Seq' which means once you choose to reply to a signal, the computer can do the rest!

This last screenshot shows the completed QSO. Over a period of about 15 minutes, enough meteors were in the right place at the right time to allow their fiery destruction to do good and reflect our messages. A final confirmation via the online chat once the QSO was complete was made, to say thanks to Jurgen for his patience.

So, if you've always thought that meteor scatter was a mode for those with 'big gun' money for huge antennas, expensive low noise GaAsFET preamps, big linear amps and costly dedicated reel to reel high speed morse tape recorders, think again, and perhaps give it a try. If your in an IO or JO square, send in the 2nd slot! (convention - South and East sending in 2nd slot, North and West sending 1st). You only need a modest station, and a lot of patience!

Wednesday, 12 July 2017

'Scope repaired, and some fun with the Rectum Paralyzer

After some time spent blasting every moving contact in sight with Servisol, and resoldering any connection that didnt look pin sharp, my Hitachi V-212 20MHz Dual Trace Oscilloscope is now back working how it should be.

Inside the scope is very tidy, but clearly many years of grime had built up on the controls, causing all manner of irregular operation. Since I had to remove many of the plugs, these were all numbered with a Sharpie type pen so I knew where to put them back!

These two photos might seem pointless - actually, they are visual references as to where the correct control knobs and nuts were to be refitted! I also found that the protective film was never removed from the front panel, and was now in a poor state, Removing the film has brought the front panel back to near new looking condition!

After putting the scope back together, and replacing all the test gear on the bench where it should be, I started to have a play with the Spectrum Analyzer. (the weight of my analyzer is why it gets the name in the title! If your not careful with your manual handling these things can give you some interesting ruptures). I had heard that it was possible to get demodulated audio out, but wasnt sure how. Several youtube videos 'almost' helped, except that the described outputs were not as described on my instrument!

I sent a post in to G-QRP forum for assistance, but in the meantime, Sam came home from school, so I commandeered him for a few minutes to swap BNC connections around on the back of the analyzer, whilst I looked at what was on them on the 'scope. My connections are marked X, Y, and Z. One of these, Z I think it was, was tried first, resulting in a pulsing DC level. Clearly not that then. X was next up and showed a large triangle wave with a long 0v period, clearly the timebase! So the final Y connection was tried - yes! The 'scope trace showed just what the zero-span display of the analyzer did. Swapping the connection from the 'scope to the audio input of the 2955B, we had demodulated audio out of the test sets loudspeaker.

Using the 2955B isnt really convenient for this though, so I found a general purpose AF amp, based on an LM386, that was kicking about the bench, and connected that up. Perfect. I now need to find a box to put the audio amp in, so I can connect it neatly to the spectrum analyzer Y output for monitoring.

I hope eventually to us it for narrowing down airband transmissions, but im not accurate nor fast enough on the analyzers controls yet to pinpoint a transmission!

Car Stereo fault - Beat 485 repair

Well, marvelous isnt it? The Marconi 2955B goes on the blink, but before I can fix it the oscilloscope requires an overhaul. Get the 'scope dismantled for cleaning, lubricating and repair, and the flipping 2955B decides to start working again, leaving me with no idea whether something ive done, like reseating the cards, has fixed it, or whether the fault is indeed temperature dependent and likely to be a real twat to narrow down,

And while all this is going on, to really piss me off, the volume control on my car stereo fails! It randomly decides whether to go up or down whichever way I turn the knob!

I have a cheap after market DAB stereo, a Beat 485. This does DAB and DAB+ (why I bought it!) plus CD, USB etc. The volume control is not a traditional potentiometer, but a rotary encoder.

No photos for this fix im afraid! But it really doesnt need any, if your capable of doing this repair then you dont need a pictorial guide!

Opening the head fascia unit up is fairly simple - four screws and case clips, easily separated using a finger nail or similar thin object. The encoder turns out to be a mechanical type. This was to be expected as optical units are far more expensive. It also is a type with a central push button action (which I didnt know about its function on the stereo - turns out it selects the tone and balance options).

Once inside the head unit, the next job was to remove the encoder. This isnt particularly easy - there is a sizeable metal casing to it soldered down at either side, plus the five switch contacts (three one side, two the other). Ideally use a good hot iron here with plenty of heat capacity! I just plodded on with the 18W Antex, but the 45W iron would have been more sensible! Once desoldered, there are four folded tags on the underside that have to be lifted to dismantle the device.

Inside, the main encoder track could be seen, with two sliding contacts either side of the shaft. The pattern of the track could barely be seen it was so dirty! A blast with Servisol and a good scrub with a brush had it clean and shiny again. A gentle push with the end of a terminal driver reset the sliding contacts.

Reassembly was just the reverse of the above, ensuring of course that everything stayed in alignment, and then giving the securing tabs a good push down. After cleaning up the terminals, resoldering the encoder to the board was simple, as was rebuilding the head unit. I removed any other muck and dust at the same time.

A quick test back in the car shows that I now have a properly functioning volume control again!

Thursday, 6 July 2017

And now the Marconi 2955B is on the blink again!

Well, this just about takes the biscuit!

Not only do I discover that my understanding of the use of my spectrum analyser is probably woefully inadequate, and that my oscilloscope is playing up and needs a service, but now my 2955B test set is on the fritz! Again!

This time, I know im at serious risk of screwing the firmware if I dont fix it. So, its time to open her up.

The 10MHz Oven Compensated Crystal Controlled Oscillator (OXCO) unit, is mounted, horrifyingly, on the same board that generates the EHT for the CRT!

Rear of the Reference/EHT board
I very much dislike playing near EHT supplies! I know from experience what a belt from the anode cap of a brand new never been connected TV tube feels like - and dont fancy experiencing the same from an actual supply! So I very carefully ensured (with a pair of long nose pliers) that the reservoir capacitors were properly discharged!

Inside the Marconi 2955B. Note the warnings!
The actual OXCO's six pins desoldered very easily, and the whole module came out smoothly. I opened it up to see if there was anything obviously wrong inside

The 10MHz OXCO... bloody complicated inside!
But other than the trimmer capacitor (which I seem to remember being told could be the problem) it all looks ok, albeit extremely complex! So, I connected it up on the bench. 12v at 120mA steady (450mA initial) for the heater, 5v via a 22ohm current limit for the oscillator. 

On the bench...
 And the damn thing seems to be working perfectly!

...and seemingly working perfectly!
 I have had it powered now for about an hour. Ive even abused it - heating it with a hot air gun until it was too hot to touch, whereby it crept up to 10.00015MHz, and freezing it until the heater current maxed out again, and it barely dropped below 9.99998MHz!

Im now at a loss, but my suspicions center around either a power supply fault, or something as insidious  as a dry joint or leakage due to old flux! Where I go from here, im not sure, and ive a ton of work piling up that requires a working test set!

Spectrum Analysis - Am I doing it Wrong?

After a lot of puzzling and pondering over the transverter, ive started to come to a slow realization that much of the problem might actually be with me!

What I mean is, im starting to think that my knowledge of how to correctly read the spectrum analyser, and hence my interpretation of the results of tests on the transverter, may be lacking in understanding.

Sadly, when I try and find tutorials online, they are either far too in depth, such as guides to measuring phase noise, or based on much more modern and advanced LCD FFT instruments, rather than the 'classical' CRT superhet instrument I have.

So I guess what I need to do is get to very thorough grip with my SA instrument and its operation, before I progress with the transverter.

Tuesday, 4 July 2017

FARS Rally - Sunday 23rd July

A quick and blatant plug for this exceptional radio rally!

The Finningley Amateur Radio Society rally is fast approaching!

Located at the club HQ near Sandtoft, this rally is one of the best component and 'junk' sales around! I myself, with Bob M1BBV, will have a stall again this year, where I hope to be able to sell on some interesting items, big on our stall this year will be batteries for the Clansman PRC-349 radios (12v in a handy sized screw in pack), 'covert' diplexers, 'Panorama' professional antenna mounts, and Kenwood TK-349 PMR handhelds. Plus all manner of other junk!

I only hope to make enough money to cover my stall fees and the cost of whatever junk I buy!!!